Efforts to identify the core elements that make verbal interaction psychologically therapeutic have usually focused on the psychotherapist's verbal behavior. However, therapists use systematically different types of verbal interventions depending on the theory of therapy they are using. By contrast, clients' verbal behavior is strikingly similar across different therapeutic approaches. Thus if there are common "active ingredients" in different psychotherapies, they might be found in the client's verbal behavior--or in the client-therapist interchange. The proposed research will examine in detail one important aspect of client-therapist verbal interaction, their speech acts toward each other, and will test hypotheses regarding the relation of client as well as therapist speech acts in therapy to the impact of sessions and psychotherapy outcome. The verbal response mode (speech act) use of 40 neurotic (anxious, depressed) clients and their therapists will be coded in 240 tape-recorded psychotherapy sessions already gathered by investigators at the MRC/ESRC Social and Applied Psychology Unit at the University of Sheffield, Sheffield, United Kingdom. In this study, clients were given eight sessions each of two contrasting types of therapy, an exploratory therapy and a prescriptive therapy, in successive phases. Measures of clients' symptoms and personality were taken before therapy; measures of session impact and symptom severity were taken each week, and measures of change and improvement were taken at the end of each phase of treatment and at three-month follow-up. The proposed research will assess (a) how contrasting therapeutic approaches influence clients' and therapists' in-session verbal behaviors and patterns of interaction, including the "verbal exchange structure" of each approach; (b) how clients' personality and symptom configuration predict response to each therapeutic approach; (c) how therapist and client verbal behaviors predict short-term session impact, including evaluations of session quality; and (d) how therapist and client verbal behaviors predict measures of psychotherapy outcome.